Ah yes, #1701014: Validate config object names is the problem exactly. Edit: well, a complement to it, maybe we need to re-scope that issue a little. So we consider breakpoint.yml an invalid config filename, and the config filename must always have two(-plus) parts?

Aside, finding the string breakpoint to replace it with breakpoint.settings within the module directory is entertaining. Here's just the file rename as a start.

Uh. The fact that #7 passes makes me wonder about breakpoint's test coverage. We just renamed breakpoint.multipliers to breakpoint.settings.multipliers, so it seems like something should fail? I guess there's no coverage for whether defaults are installed.

Yeah, as far as I can tell Breakpoint doesn't even use what's in that yaml file at all, so we're not actually even breaking anything that isn't already broken. Maybe it was intended for use once a UI was added?

Per webchick's request I tested existing breakpoints in standard with this patch applied and confirmed none of the behavior changes. The toolbar still flips its orientation from horizontal to vertical, and the primary navigation still switches from tabs to touch buttons. The text labels next to the icons also still get hidden.

Hm. Let's definitely get a follow-up (probably a "major task") to figure out what's happening w/ Breakpoint module. I remember that going in with some weird workaround stuff for CMI that are probably still there, and I definitely didn't expect Toolbar to continue to work, since AFAIK it's piggy-backing off the Breakpoint module definitions.

In the meantime though, this seems simple enough, so committed and pushed to 8.x. Thanks!

In that case, we should keep the existing test coverage assertion (since it was introduced for a reason), but call ->listAll() two times, once without and once with module prefix, and assert that $all_names is non-empty.